Follow-up actuating mechanism for pressing machines



' Nov. 1, 1932. E. DAVIS 1,885,235

FOLLOW-UP ACTUATING MECHANISM FOR PRESSING MACHINES Filed July 3, 1929 3 Sheets-Sheet 1 INVENTOR.

A TTORNEYS NOV. 1, 1932. v 1,885,235

FOLLOW-UP ACTUATING MECHANISM FOR PRESSING MACHINES Filed July 3, 1929 3 Sheets-Sheet '2 L zrki I II i I 1 13" I I l I' i Mi M I!!! .BY W

A TTORNEYS Nov. 1, 1932. DAVls 1,885,235

FOLLOW-UP ACTUATING MECHANISM FOR PRESSING MACHINES Filed July 3, 1929 3 Sheets-Sheet 3 IN VEN TOR.

A TTORNEYS Patented Nov. 1, 1932 UNITED STATES PATENT", OFFICE ERNEST DAVIS, OF SYRACUSE, NEW YORK, ASSIGNOR TO THE PROSPERITY COMPANY INC F SYRACUSE, NEW YORK, A CORPORATION OF NEW YORK FOLLOW-UP ACT'Q'A'IING MECHANISM FOR PRESSING MACHINES Application med July 3, 1929. Serial No. 375,682.

This invention relates to pressing machines simple and eflicient actuating mechanism.

whereby a full predetermined pressure is delivered to the movable pressing element, regardless of the thickness of the work or padding, or the amount of compression of the padding on one or both of the elements.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention reference is had to the accompanying drawings'in which like characters designate corresponding parts in all the views.

Figure 1 is a side elevation, partly broken away, of a machine embodying myinvention.

Figure 2 is an enlarged vertical sectional view through the actuating means for the movable element.

Figure 3 is a diagrammatic view of the controls of the actuating means.

Figure 4 is a view similar to Figure 2 of another form of my invention omitting the check valve and the power means for closing it.

n some types of pressing machines, the movable elements or heads are actuated through toggle mechanism or the like and as the greatest pressure can, only be obtained when the toggle approaches a straight line, the amount of pressure is limited to that delivered when the toggle is in a straight line and the pressure is constantly being varied by changes in the thickness of the work and of the padding as the padding settles under continued use of the machine. Frequent adjustments of the toggle to keep the pressure uniform are necessary'and if the adjustments are not made, the machine does not function efliciently and the quality of the work is not up to standard.

In machines where the power is applied by a "cylinder and piston in which the piston is connected to the movable element in such a way that the amount of pressure delivered is commensurate with the movement'of the piston, a comparatively large cylinder, or

actuating mechanismmotive fluid under great head of pressure, is required because a long movement of the piston with very little power is required to close the press, while a short movement of the piston under excessive pressure is required to close the press under heavy pressure and compress the padding. Hence, a cylinder large enough to deliver final heavy pressure is much too large to merely close the press and requires a motive fluid under high pressure and is therefore wasteful in the use of the motive fluid.

The primary object of this invention is to provide an actuating mechanism which preliminarily closes the press from wide open to closed position and then boosts the pressure or applies heavy pressure without repivoted at 6 between its ends to an upright 7 rising from the frame.

' The actuating mechanism is connected to the rear arm of the lever 5 and acts directly against the same in contra-distinction to acting indirectly through toggle mechanism and the like which reaches a final position where it will not transmit further movement.

The actuating mechanism comprises an actuator having a" comparatively great movement to close the press from wide open to closed position and a comparatively small powerful movement from preliminary closed position intofin'al pressure position, a second actuator having a comparatively great amount of movement relative to the first actuator when the press is moving under final pressure, means whereby the comparatively large movement of the second actuator is translated into a small powerful short movement to the first actuator, and means for controlling the operation of the actuators successively. reciprocating.

One actuator comprises a piston 9 movable in a cylinder 10, the rod 11 of the piston being connected directly at 12 to the rear arm of the yoke lever 5 so that all the movement of the piston 9 is efiectively transferred to the head 2 and is not limited as in machines having toggle mechanism in which the toggle reaches a straight line.

A second or booster cylinder 13 has a reciprocating actuator or plunger 14 therein, this being of small diameter relatively to the cylinder 10 and communicating with the cylinder 10 at one end thereof. Both the piston 9 and the plunger 14 are single acting and the press is opened, when the pressure 1s released, by countersprings 15 connected to the rear arm of the yoke lever 5. The piston 9 is actuated to preliminarily close the press by a hydraulic fluid as oil 16 located in a reservoir 17. The pressure is applied to the body of the oil 16 in any suitable manner and usually air pressure is applied and the air pressure controlled by the operator as will be presently described.

The reservoir 17 in the illustrated embodiment of my invention communicates with the lower end of the cylinder 10 through the booster cylinder 13 and a passage 18 having a check valve 19 therein. Air is supplied to the upper part of the reservoir 17 through a pipe 20 and when air is permitted to flow through the pipe 20 into the reservoir 17 against the surface of the body of the oil 16 therein, the oil is forced through the passage 18, cylinder 13, and into the cylinder 10 actuating the piston 9 therein upwardly to close the press. The movement of the piston 9 is comparatively long but requires little pressure to close the press. The movement of the piston 9 takes place until the resistance of the work and padding equals the oil pressure against the piston 9.

The check valve 19 is held open by a. spring and is held closed, in the construction shown in Figure 2, against the action of the spring by power means. In Figure 4, the check valve and operating means therefor is omitted as will be more fully described.

The booster plunger 14 is actuated, in the illustrated embodiment of my invention, to apply final heavy pressure by a cylinder 21 having a piston 22 therein, the rod 23 of which is connected to a plunger 14, and the pressure end of the cylinder 22 is connected by a pipe 24 to a supply of compressed air. The flow of compressed air to the reservoir 17 and the cylinder 21 takes place successive- 1y. The plunger 14 has a comparatively long movement relatively to the movement ofthe piston 9 to move the piston when actuating the head from preliminary closed position to final pressure position and the comparatively.

long movement thereof is translated to the Lesaaae Both actuators are here shown as piston 9 by the oil in the cylinders 13 and 10.

As the diameter of the cylinder 10 is considerably larger than that of the cylinder 13, the long movement of the plunger 14 is translated into a short heavy pressure movement to the piston 9.

The air is supplied from a suitable feed line 25 and the flow of air is controlled through the pipe 20 to the chamber 17 through a manually operated valve mechanism comprising a valve casing 26 having a normally closed, spring-pressed intake valve 27 and a normally open exhaust valve 28 therein, these valves being connected by a stem 29 so that they act as a unit. The valve casing 26 is connected at a point between the valves to the pipe 20. The valves are operated by suitable means here shown as a push button 30 acting on a lever 31 WhlCl] in turn acts upon the stem 32 of the exhaust valve 28. A spring 33 returns the push button to its starting position. In order that two hands may be required to effect the closing of the press, a second push button 34 is employed which through a lever 35 acts upon the stem of a normally open exhaust valve 36 in a valve casing 37 which is connected by a pipe 38 to the pipe 20.

Depression of the two push buttons 30 and 34 closes the exhaust valve 28 and opens the intake 27 and also closes the exhaust valve 36 so that air passes from the feed line 25 through the valve casing 26, and pipe 20 to the oil reservoir 17 and the pressure of the air on the oil therein forces the oil through the passage 18, and cylinder 13, into the cylinder 10 to actuate the piston 9 upwardly and close the press until the resistance of the work and padding equals the pressure of the oil. If the push button 34 is not depressed, the air instead of passing from the pipe 20 into the reservoir 17 'will pass out through the pipe 38, valve casing 37, and the outlet 39 controlled by the exhaust valve 36. Thus, both push buttons must be depressed to effect the closing of the press.

Preferably, the flow of air successivelv to the chamber 17 and cylinder 21 is controlled by manual means, and the flow of air to the cylinder 21 is controlled by a valve casing 40 having at normally closed, springpressed intake valve 41 and a normally open exhaust valve 42 therein, these two valves being connected by a stem 43 so that they act as a unit. The casing is connected at its intake end by a pipe 44 to the feed pipe 25 and at a point between its ends by the pipe 24 to the intake end of the cylinder 21. These valves are operated by a manually operated lever 45 having an arm 46 coacting with the stem of the exhaust valve 42.

Obviously, upon movement upwardly of the lever 43, the exhaust valve 42 will be closed and the intake valve 41 opened so that air is free to pass from the feed line 25,

through pipe 44, valve casing 40, and pipe 24, to the cylinder 21 to actuate the piston 22 therein and thus actuate the plunger 14. The valves 41 and 42 are locked in their operated position by a diaphragm 47 in a chamber 48, the pressure side of which is connected by a duct 49 to the interior of the valve casing 40. The diaphragm acts on the sliding stem 50 which thrusts against an arm 51 of the lever 45. Thus, when the lever 45 is operated, the valves 41 and 42 will be immediately locked in their operated position so that the press will be heldclosed as long as desired. 7

To open the press, the lever 45 is moved downwardly against the pressure of the diaphragm 47, thus permitting the intake valve 41 to close and the exhaust valve 42 to open and hence, the air to exhaust back through the pipe 24 and through the valve casing 40.

The check valve 19 is closed and held in its closed position against the action of a spring 52 tending to open it by locking means controlled by the lever 45. The locking means, here shown, comprises a diaphragm chamber 53 having a diaphragm 54 therein acting on a sliding stem 55 which in turn acts upon one arm of a lever 56 pivoted at 57 on the top of the reservoir 17; the other arm of this lever 56 being connected to the stem 58 of the check valve. The pressure side of the diaphragm chamber 53 is connected by a pipe 59 in the air conduit system controlled by the lever 45, it being here shown as being connected to the pipe 24. Thus, when the lever 45 is moved upwardly, to open the intake valve 41 and close the exhaust valve 42, the air not only flows to the cylinder 21 but also the pipe 59 through to the diaphragm chamber 53 to actuate the diaphragm 54 therein and hold closed the check valve 19.

In Figure 4, the reservoir 17 opens into the cylinder 13 through an open port 61 located so that it will be covered or cut off by the plunger 14 upon the initial part of its actuating movement by the piston 22 in the in the cylinder 21. The control mechanism for the construction shown in Figure 4 is the same as for that shown in Figure 2 with the exception that there being no check valve, the diaphragm chamber 53 and associated parts, including the pipe 59, are omitted.

In operation, the operator first depresses both push buttons 30 and 34 and if he desires to lock the press closed, he lifts upwardly on the lever 45 before he releases the push buttons 3C and 34. The lever 45 is grouped with one of these push buttons so as to be readily operated. WVhen the hand is holding down one of the push buttons, the pressure of the air on the upper surface of the oil 16 closes the press by moving the piston 9 through a comparatively long movement until the piston is stopped by the resistance of the buck and the work thereon to the head.

Upon moving the lever 45 upwardly, the check valve 19 will be closed thus preventing the escape of oil from the cylinder 10 back to the reservoir 17 and also the intake valve 41 will be opened and the exhaust valve 42 closed permitting air to enter the cylinder 21 and actuate the piston 22 and hence, actuate the plunger 14 thus boosting the pressure in the cylinder 10 and closing the press under final heavy pressure. The press will be locked in closed position by action of the diaphragm 47 as above described. To open the press, the lever 45 is moved downwardly. If the lever 45 is operated in advance of the push buttons 30 and ,34, the piston 9 will be actuated but a small distance and consequently the head will not move very far towards closed position. For effective operation, both push buttons must be first depressed. Owing to this invention, it is obvious that the press will always be closed-under a predetermined heavy' or final pressure regardless of the thickness of the work or thickness der and piston hydraulic motor to close the press successively under light and heavy mo pressure; a hydraulic fluid reservoir connected to the cylinder of said hydraulic motor; a normally open passage communicating with the reservoir and the cylinder; a compressed air supply line connected to said reservoir; first operator-operated control means in the connection between the supply line and the reservoir operable to supply compressed air thereto to displace the hydraulic fluid and actuate the hydraulic motor to close the press under light pressure and normally in a position to exhaust the air from the reservoir; compressed air operated means for closing said passage and applying additional pressure to the hydraulic fluidin the cylinder including a member movable into the hydraulic fluid in the cylinder to displace the same while the passage is closed; and a second operator-operated control means operable to connect the compressed air supply line with said compressed air operated means while the first operator-operated control means are in operated position and normally in a position to exhaust the air from the air operated means.

In testimony whereof, I have hereunto slgned my name, at Syracuse, in the county of Onondaga, and State of New York, this 21st day of June, 1929.

ERNEST DAVIS. 

